Stir the lard and egg into the warm mashed potatoes until throughly incorporated. Combine crushed pork rinds with flour, and stir into potatoes. Season to taste with salt if needed. Form into golf ball sized pieces on a lightly floured surface, then press to form into disks about 3/4 inch thick. Heat the oil in a large skillet over med. heat. Fry the chapaleles on both sides until crisped and golden brown, 4 to 5 min. per side. Other option: They may be baked in a 375 oven until golden brown, about 25 min.